Heat Sink and Electronic Device and Heat Exchanger Applying the Same

ABSTRACT

A heat sink includes a substrate, at least a first fin set and at least a second fin set. The first fin set is disposed on the substrate and has a plurality of first fins, and the first fin has a plurality of first holes. The second fin set is disposed on the substrate and has a plurality of second fins, and the second fin has a plurality of second holes. The total area of the second holes is larger than that of the first holes. An electronic device and a heat exchanger which are configured with the heat sink are also disclosed. The structure and configuration of the heat fins can increase the wind guiding effect, and thus improve the heat-dissipation efficiency.

CROSS REFERENCE TO RELATED APPLICATIONS

This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 201210243375.1 filed in People's Republic of China on Jul. 13, 2012, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a heat sink and an electronic device and a heat exchanger using the same.

2. Related Art

After the great progressive of electronic industry, the operation speed and performance of electronic elements are increased, and thus, the heat dissipation has become a very important issue for affecting the operation performance and stability. In order to normally operate the electronic device, it is common to provide a heat sink on the electronic element that can generate heat, so that the generated heat can be properly dissipated through the heat sink.

The conventional heat sinks for electronic devices mainly use the stacked fins to transmit the heat out. Under the considerations of installation volume and environment, most fins are positioned inside the casing of the electronic device, so it is need to configure an auxiliary component (e.g. a fan) for facilitating the heat dissipation. However, the achieved heat-dissipation effect is still limited. In other words, there still exist some heats inside the closed casing, which may damage the internal electronic element of the electronic device.

In addition, the heat sink for the closed electronic device must satisfy the limitations of the manufacturing processes and designs of the electronic device, so that the conventional stacked fins have reached the bottleneck of heat dissipation. Some heat sinks comprise modified fins, which have improved shapes or microstructures, for enhancing the conductive ability. However, in a closed electronic device, which needs to consider the air input channel and heat-dissipating speed simultaneously, the applied fins usually have more complex design and installation, so that the manufacturing time and cost are definitely increased.

Therefore, it is an important subject to provide a heat sink that has simple design and configuration and can effectively increase the air input quantity so as to improve the heat-dissipating speed and increase the heat-dissipating performance.

SUMMARY OF THE INVENTION

In view of the foregoing subject, an objective of the present invention is to provide a heat sink that has simple design and configuration and can effectively increase the air input quantity so as to improve the heat-dissipating speed. In addition, the heat sink of the invention includes fins with special microstructure and distribution so as to increase the heat-dissipating performance.

To achieve the above objective, the present invention discloses a heat sink including a substrate, a first fin set and a second fin set. The first fin set is disposed on the substrate and has a plurality of first fins, and each of the first fins has a plurality of first holes. The second fin set is disposed on the substrate and located adjacent to the first fin set. The second fin set has a plurality of second fins, and each of the second fins has a plurality of second holes. The total area of the second holes is larger than that of the first holes.

In one embodiment, the first fin set is disposed adjacent to an outlet, and at least a fan is configured at the outlet.

In one embodiment, the heat sink is disposed in a casing having a first inlet, the second fin set is disposed adjacent to the first inlet, and the second holes are opposite to the first inlet.

In one embodiment, the casing further has at least a second inlet, and the second inlet is opposite to at least a part of the first fins and the second fins.

In one embodiment, the casing further has at least a side plate disposed at one side of the substrate and located adjacent to the outlet.

In one embodiment, the heat sink further comprises a third fin set disposed on the substrate and located between the first fin set and the second fin set. The third fin set has a plurality of third fins, and each of the third fins has a plurality of third holes. The total area of the third holes is between those of the first holes and the second holes.

To achieve the above objective, the present invention also discloses an electronic device, comprising a first casing, a heat sink, and an electronic element. The heat sink is configured at one side of the first casing and comprising a substrate, a first fin set and a second fin set. The substrate and the first casing form an accommodating space. The first fin set is disposed on the substrate and has a plurality of first fins, and each of the first fins has a plurality of first holes. The second fin set is disposed on the substrate and located adjacent to the first fin set. The second fin set has a plurality of second fins, and each of the second fins has a plurality of second holes. The electronic element is disposed in the accommodating space. The total area of the second holes is larger than that of the first holes.

In one embodiment, the first fin set is disposed adjacent to an outlet, and at least a fan is configured at the outlet.

In one embodiment, the heat sink is disposed in a second casing having a first inlet, the second fin set is disposed adjacent to the first inlet, and the second holes are opposite to the first inlet.

In one embodiment, the second casing further has at least a second inlet, and the second inlet is opposite to at least a part of the first fins and the second fins.

In one embodiment, the second casing further has at least a side plate disposed at one side of the substrate and located adjacent to the outlet.

In one embodiment, the heat sink further comprises a third fin set disposed on the substrate and located between the first fin set and the second fin set. The third fin set has a plurality of third fins, and each of the third fins has a plurality of third holes. The total area of the third holes is between those of the first holes and the second holes.

To achieve the above objective, the present invention further discloses a heat exchanger, comprising a heat sink and a heat absorber. The heat sink comprises a substrate, a first fin set and a second fin set. The first fin set is disposed on the substrate and has a plurality of first fins, and each of the first fins has a plurality of first holes. The second fin set is disposed on the substrate and has a plurality of second fins, and each of the second fins has a plurality of second holes. The heat absorber is disposed at one side of the substrate opposite to the heat sink. The total area of the second holes is larger than that of the first holes.

In one embodiment, the first fin set is disposed adjacent to an outlet, and at least a fan is configured at the outlet.

In one embodiment, the heat sink is disposed in a casing having a first inlet, the second fin set is disposed adjacent to the first inlet, and the second holes are opposite to the first inlet.

In one embodiment, the casing further has at least a second inlet, and the second inlet is opposite to at least a part of the first fins and the second fins.

In one embodiment, the casing further has at least a side plate disposed at one side of the substrate and located adjacent to the outlet.

In one embodiment, the heat sink further comprises a third fin set disposed on the substrate and located between the first fin set and the second fin set. The third fin set has a plurality of third fins, and each of the third fins has a plurality of third holes. The total area of the third holes is between those of the first holes and the second holes.

In summary, the heat sink of the invention includes the first and second fins having the holes with different intervals. Thus, when the first and second fins are properly configured with respect to the inlet, the holes with different intervals can form a channel parallel to the airflow direction. After the air enters from the inlet, it travels through the holes with smaller intervals in advance and then through the holes with larger intervals. In other words, the air enters the heat sink and flows through the fins with higher hole density and then lower hole density in sequence. This feature can speed up the airflow passing through the fins and thus further improve the heat-dissipation efficiency.

In addition, the heat sink of the invention may further cooperate with a casing, which is configured with a lateral inlet, and the above-mentioned fins are partially exposed from the casing. This configuration can effectively enhance the lateral air input quantity and intensity so as to further improve the heat dissipation performance. In practice, the heat sink of the invention can be applied to an electronic device so as to achieve a better heat dissipation for a closed device. Compared with the conventional art, the heat sink of the invention can provide more air input quantity for a closed device, thereby increasing the heat-dissipating speed of the electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the subsequent detailed description and accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1A is a schematic diagram showing a heat sink according to an embodiment of the present invention;

FIG. 1B is a front view of the heat sink of FIG. 1A;

FIG. 2A is a schematic diagram showing a heat sink according to another embodiment of the present invention;

FIG. 2B is a schematic diagram showing a heat sink according to another embodiment of the present invention; and

FIG. 3 is a schematic diagram showing an electronic device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

FIG. 1A is a schematic diagram showing a heat sink H according to an embodiment of the present invention, and FIG. 1B is a front view of the heat sink H of FIG. 1A. Referring to FIGS. 1A and 1B, the heat sink H includes a substrate S, at least a first fin set 1 and at least a second fin set 2. In order to achieve the desired heat dissipation, the heat sink H has a first inlet I1 and an outlet O, so that the air or gas can enter the first inlet I1, pass through the interior of the heat sink H to carry out the heat exchange, and then exit via the outlet O. The features of the structures of the heat sink H will be described hereinbelow.

The first fin set 1 and the second fin set 2 are all disposed on the substrate S. The first fin set 1 is located close to the outlet O, and at least one fan (not shown) is configured at the outlet O. The second fin set 2 is located closer to the first inlet I1 of the heat sink H than the first fin set 1. In other words, the second fin set 2 is disposed at a position on one side of the substrate S closer to the first inlet I1. The first fin set 1 has a plurality of first fins 11, and each first fin 11 has a plurality of first holes 111. A first interval 112 is configured between two adjacent first holes 111. Similarly, the second fin set 2 has a plurality of second fins 21, and each second fin 21 has a plurality of second holes 211. A second interval 212 is configured between two adjacent second holes 211. Herein, the “holes” are recesses or gaps formed on the fin by cutting or punching. However, it is not limited to the cutting or punching method, and the “holes” can be made by any other processes. For example, in other embodiments, the fins and the substrate can be made of a single material and substantially integrally formed, so that the holes are formed during the formation of the fins and substrate. This method can obtain a heat sink structure with better strength.

The total area of the second holes 211 is larger than that of the first holes 111. In other words, the first interval 112 is larger than the second interval 212. The distribution density of the second holes 211 on the second fin 21 is greater than that of the first holes 211 on the first fin 11. Moreover, within the same length, the number of the second holes 211 configured on the second fin 21 is larger than the number of the first holes 111 configured on the first fin 11. When the number of the first holes 111 is less than that of the second holes 211, the dimensions of each first hole 111 and each second hole 211 are substantially the same. Of course, the dimensions of each first hole 111 and each second hole 211 can be different. This configuration can also achieve the purpose of providing the total area of the second holes 211 of the second fin 21 to be larger than that of the first holes 111 of the first fin 11.

In this embodiment, the first fin set 1 includes a plurality of first fins 11, and the second fin set 2 includes a plurality of second fins 21. That is, the heat sink H includes two fin sets, each of which has the holes with the same interval (the intervals of different fin sets are different). After stacking multiple fin layers to form the fin set, the number of fins having the holes with the same interval can be increased. When the airflow passes through the fins with increasing intervals, the flow rate of the airflow can be increased.

In more detailed, the first holes 111 configured on the first fins 11 of the first fin set 1 form a first channel 113 parallel to the airflow direction along the perpendicular direction. Similarly, the second holes 211 configured on the second fins 21 of the second fin set 2 form a second channel 213 along the perpendicular direction. In this embodiment, taking the first fin set 1 and the second fin set 2 as an example, when the airflow flows from the bottom of the second fin set 2 to the first fin set 1, it firstly passes through the second fins 21. Since the second holes 211 of the second fins 21 are the same, it is possible to provide a longer second channel 213, which can protect the airflow converged to the second holes 211 from interference and allow the airflow to flow toward the first fins 11 smoothly.

In this embodiment, the heat sink H further includes a third fin set 3, which is disposed on the substrate S and located between the first fin set 1 and the second fin set 2. Similarly, the third fin set 3 has a plurality of third fins 31, and each third fin 31 has a plurality of third holes 311. The total area of the third holes 311 is between the total areas of the first holes 111 and the second holes 211. A third interval 312 is configured between two adjacent third holes 311, so that the third interval 312 is between the first interval 112 and the second interval 212. In more detailed, regarding to the arrangements of the fins in the heat sink H, the distribution density of the second holes 211 is larger than that of the third holes 311, and the distribution density of the third holes 311 is larger than that of the first holes 111. Of course, the numbers of the fins are not limited. For example, it is possible to configure a fourth fin set, a fifth fin set, . . . , and/or an nth fin set between the first fin set 1 and the second fin set 2. The configuration of the fin sets is determined according to the application of the heat sink or the dimension and heat-dissipating requirement of the applied device. The most important is to design the fins with the holes and intervals following the concept and relationship of the above-mentioned first fin set 1, second fin set 2 and third fin set 3.

In practice, the fan (not shown) configured at the outlet O of the heat sink H can drive the airflow entered from the first inlet 11 at the bottom of the heat sink H to flow through the second holes 211, the third holes 311 and the first holes 111 in sequence. Since the second interval 212 between the second holes 211 of the second fins 21 closer to the first inlet I1 is smaller, which means the distribution density of the second holes 212 is higher, the air quantity allowed to pass through the second fins 21 is larger than those allowed to pass through the third fins 31 and the first fins 11. Accordingly, the speed of the airflow increases as the intervals of the holes change when the airflow travels from the second fins 21 to the first fins 11. Besides, since the intervals are different, the holes of different fins are not totally communicated. In other words, the projection of the second holes 211 of the second fin 21 is not completely overlapped with the projection of the third holes 311 of the third fin 31. Thus, the airflow can form a temporary turbulent flow between two fin sets as the airflow flows through different fin sets. This feature can enhance the heat exchange rate and thus improve the heat-dissipation ability of the heat sink H.

FIG. 2A is a schematic diagram showing a heat sink H1 according to another embodiment of the present invention. Referring to FIG. 2A, the structure of the heat sink H1 is almost the same as that of the heat sink H of the previous embodiment. Their different is in that the heat sink H1 includes four fin sets, and the relative relationship of the four fin sets is configured based on the concept of the heat sink H of the previous embodiment. The heat sink H1 is disposed in a casing 5, and the casing 5 is connected to the substrate S. Herein, the casing 5 includes two side plates 51 and a front plate 52. The casing 5 is substantially covering a first fin set 1, a second fin set 2, a third fin set 3 and a fourth fin set 4, so that the airflow can only enter the heat sink H1 through the first inlet I1. This configuration can effectively concentrate the airflow entering the heat sink H1 and speed up the airflow to pass the channels rapidly. To be noted, since the intervals of the holes in the fin sets are different, the channels are not completely communicated correspondingly. Taking the fourth channel 413 and the third channel 313 as an example, when the airflow flows between the fourth channel 413 and the third channel 313, a temporary turbulent flow can be formed between the topmost fourth fin 41 in the fourth fin set 4 and the lowest third fin 31 in the third fin set 3. This feature can enhance the heat exchange rate and thus improve the heat-dissipation ability. The similar effect can be obtained between other fin sets, so the detailed descriptions will be omitted.

FIG. 2B is a schematic diagram showing a heat sink H2 according to another embodiment of the present invention. Referring to FIG. 2B, the structure and features of the heat sink H1 are almost the same as those of the heat sink H1 of the previous embodiment. Their different is in that the heat sink H2 is disposed in a casing 5 a, and the two side plates 51 a of the casing 5 a are not completely covering the fin sets. Under this configuration, the casing 5 a further includes a second inlet 12 located at one of the side plates 51 a and between the front plate 52 and the substrate S, so that the second inlet 12 is opposite to at least a part of the first fin set 1 and the second fin set 2. In other words, except for the first inlet I1 configured at the bottom, the heat sink H2 further includes a plurality of second inlets 12 which allow the airflow to enter the heat sink H2. In brief, more air quantity can enter the heat sink H2 through the first inlet I1 and the second inlet(s) 12, so that the heat-dissipation effect can be improved. Herein, the second inlet(s) 12 allow the airflow(s) to directly enter the area(s) between different fin sets. In this embodiment, the intervals between different fin sets and the fins of each fin set are all equal to each other, so the dimensions of the second inlets 12 are the same.

In this embodiment, the ratio of the heights of the side plate 51 a and the front plate 52 is 1:4, which can enhance the airflow guiding effect of the fin sets with holes of different distribution densities according to this invention. To be noted, the dimension and shape of the side plate are not limited in this invention. In other embodiments, the ratio of the heights of the side plate and the front plate can be, for example, 1:3 or 1:2. In general, when the height of the side plate is closer to that of the front plate, the heat sink has better effects in the functions of dustproof and preventing objects from entering the heat sink.

FIG. 3 is a partial exploded view of an electronic device 6 according to an embodiment of the present invention. With reference to FIG. 3, the electronic device 6 includes a first casing 61, a heat sink H′ and an electronic element 62. The structure and feature of the heat sink H′ are almost the same as those of the heat sink H of the previous embodiment, so the detailed description thereof will be omitted. Their difference is in that the casing 5 of FIGS. 2A and 2B is referred to a second casing 64 of FIG. 3. The substrate S of the heat sink H′ and the first casing 61 form an accommodating space 65, and the electronic element 62 is disposed in the accommodating space 65. In this embodiment, the electronic device 6 is a cabinet. Of course, the electronic device of the invention can be any device containing an electronic element to be cooled down.

In this embodiment, the electronic device 6 further includes at least one fan 63, which is disposed adjacent to an outlet O of the heat sink H′ for exhausting the airflow after traveling through the heat sink H′, thereby enhancing the heat dissipation efficiency. Alternatively, the heat sink H′ can be directly disposed on the electronic element 62 and connected to the electronic element 62 through the substrate S. Their connection can be carried out by, for example but not limited to, locking, wedging, or soldering. Besides, the size, number and exactly connection relation of the fan(s) are not limited and can be configured based on the heat-dissipation requirement and structure of the electronic device. In other embodiments, the electronic device may further include other heat-dissipating element such as heat pipe or condensing pipe.

In this embodiment, the electronic device 6 is cooperated with a heat exchanger E, which includes the above-mentioned heat sink H′ and a heat absorber 7. The structure and feature of the heat sink H′ of the heat exchanger E are the same as those of the heat sink H of the previous embodiment, so the detailed description thereof will be omitted. The heat absorber 7 is disposed at the other side of the substrate S opposite to the location of the heat sink H′. In more detailed, the heat of the electronic element 62 can be conducted to the heat sink H′ through the heat absorber 7, so that the external cold air and the internal hot air can be cycled between the heat sink H′, the heat absorber 7 and the fan 63. Accordingly, the heat of the electronic element 62 can be dissipated via the heat exchanger E. In this embodiment, the heat absorber 7 is composed of a plurality of fins (not shown). In practice, the heat absorber 7 can be any other heat absorbing device and this invention is not limited to this embodiment.

In summary, the heat sink of the invention includes the first and second fins having the holes with different intervals. Thus, when the first and second fins are properly configured with respect to the inlet, the holes with different intervals can form a channel parallel to the airflow direction. After the air enters from the inlet, it travels through the holes with smaller intervals in advance and then through the holes with larger intervals. In other words, the air enters the heat sink and flows through the fins with higher hole density and then lower hole density in sequence. This feature can speed up the airflow passing through the fins and thus further improve the heat-dissipation efficiency.

In addition, the heat sink of the invention may further cooperate with a casing, which is configured with a lateral second inlet, and the above-mentioned fins are partially exposed from the casing. This configuration can effectively enhance the lateral air input quantity and intensity so as to further improve the heat dissipation performance. In practice, the heat sink of the invention can be applied to an electronic device so as to achieve a better heat dissipation for a closed device. Compared with the conventional art, the heat sink of the invention can provide more air input quantity for a closed device, thereby increasing the heat-dissipating speed of the electronic device.

Although the present invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the present invention. 

What is claimed is:
 1. A heat sink, comprising: a substrate; a first fin set disposed on the substrate and having a plurality of first fins, wherein each of the first fins has a plurality of first holes; and a second fin set disposed on the substrate and located adjacent to the first fin set, wherein the second fin set has a plurality of second fins, and each of the second fins has a plurality of second holes; wherein, the total area of the second holes is larger than that of the first holes.
 2. The heat sink of claim 1, wherein the first fin set is disposed adjacent to an outlet, and at least a fan is configured at the outlet.
 3. The heat sink of claim 2, wherein the heat sink is disposed in a casing having a first inlet, the second fin set is disposed adjacent to the first inlet, and the second holes are opposite to the first inlet.
 4. The heat sink of claim 3, wherein the casing further has at least a second inlet, and the second inlet is opposite to at least a part of the first fins and the second fins.
 5. The heat sink of claim 3, wherein the casing further has at least a side plate disposed at one side of the substrate and located adjacent to the outlet.
 6. The heat sink of claim 1, further comprising: a third fin set disposed on the substrate and located between the first fin set and the second fin set, wherein the third fin set has a plurality of third fins, each of the third fins has a plurality of third holes, and the total area of the third holes is between those of the first holes and the second holes.
 7. An electronic device, comprising: a first casing; a heat sink configured at one side of the first casing and comprising: a substrate, wherein the substrate and the first casing form an accommodating space, a first fin set disposed on the substrate and having a plurality of first fins, wherein each of the first fins has a plurality of first holes, and a second fin set disposed on the substrate and located adjacent to the first fin set, wherein the second fin set has a plurality of second fins, and each of the second fins has a plurality of second holes; and an electronic element disposed in the accommodating space; wherein, the total area of the second holes is larger than that of the first holes.
 8. The electronic device of claim 7, wherein the first fin set is disposed adjacent to an outlet, and at least a fan is configured at the outlet.
 9. The electronic device of claim 8, wherein the heat sink is disposed in a second casing having a first inlet, the second fin set is disposed adjacent to the first inlet, and the second holes are opposite to the first inlet.
 10. The electronic device of claim 9, wherein the second casing further has at least a second inlet, and the second inlet is opposite to at least a part of the first fins and the second fins.
 11. The electronic device of claim 9, wherein the second casing further has at least a side plate disposed at one side of the substrate and located adjacent to the outlet.
 12. The electronic device of claim 7, wherein the heat sink further comprises: a third fin set disposed on the substrate and located between the first fin set and the second fin set, wherein the third fin set has a plurality of third fins, each of the third fins has a plurality of third holes, and the total area of the third holes is between those of the first holes and the second holes.
 13. A heat exchanger, comprising: a heat sink comprising: a substrate, a first fin set disposed on the substrate and having a plurality of first fins, wherein each of the first fins has a plurality of first holes, and a second fin set disposed on the substrate and having a plurality of second fins, wherein each of the second fins has a plurality of second holes; and a heat absorber disposed at one side of the substrate opposite to the heat sink; wherein, the total area of the second holes is larger than that of the first holes.
 14. The heat exchanger of claim 13, wherein the first fin set is disposed adjacent to an outlet, and at least a fan is configured at the outlet.
 15. The heat exchanger of claim 14, wherein the heat sink is disposed in a casing having a first inlet, the second fin set is disposed adjacent to the first inlet, and the second holes are opposite to the first inlet.
 16. The heat exchanger of claim 15, wherein the casing further has at least a second inlet, and the second inlet is opposite to at least a part of the first fins and the second fins.
 17. The heat exchanger of claim 15, wherein the casing further has at least a side plate disposed at one side of the substrate and located adjacent to the outlet.
 18. The heat exchanger of claim 13, wherein the heat sink further comprises: a third fin set disposed on the substrate and located between the first fin set and the second fin set, wherein the third fin set has a plurality of third fins, each of the third fins has a plurality of third holes, and the total area of the third holes is between those of the first holes and the second holes. 